金属熔融沉积成型制备7075铝合金的显微组织和力学性能  

Microstructure and mechanical properties of 7075 aluminum alloy prepared by metal fused deposition modeling

作　　者：孙亿 易中怀 沈廷 熊慧文[1] 康潇 张雷[1] 周科朝[1] Yi SUN;Zhong-huai YI;Ting SHEN;Hui-wen XIONG;Xiao KANG;Lei ZHANG;Ke-chao ZHOU(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第7期2108-2119,共12页中国有色金属学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(No.2021YFB3701900)。

摘　　要：以优化后的微晶蜡基喂料为原料,通过金属熔融沉积成型制备3D 7075 Al合金。通过热压实验评估蜡基黏合剂和粉末之间的亲和力,研究烧结铝合金的物相、形态演变、拉伸强度和摩擦性能。打印喂料表现出剪切变稀行为,可使熔融挤出过程变流畅,并获得较好表面质量且含少量层间堆积孔隙的3D坯件。在氮气中烧结铝合金的形态演变可分为4个阶段,包括500℃下Mg_(2)Si和Si的沉淀,560℃以上Mg_(2)Si的出现,合金粉末上氧化物层的氮化,以及620℃以上通过扩散过程增强的晶粒生长。3D 7075 Al合金的相对密度达95%,拉伸强度为120~141MPa,拉伸应变为1.0%~2.5%。An optimized microcrystalline wax-based feedstock was used to fabricate 3D 7075 Al alloy through metal fused deposition modeling(Metal-FDM).The affinity between the wax-based binders and powders was evaluated by a hot-press experiment.The phases,morphology evolution,tensile strength and friction performance of the sintered Al alloy were studied.The feedstock displayed shear-thinning behavior for a smooth extrusion process,resulting in a satisfactory surface quality and minimal stacking pores in the 3D structure.The morphology evolution of Al alloy sintered in nitrogen could be divided into four stages,including the precipitation of fine Mg_(2)Si and Si at 500°C,appearance of Mg_(2)Si phase over 560°C,nitridation of the oxide layers on alloy powders and enhanced grain growth via the diffusion process over 620°C.The 3D 7075 Al alloys achieved a high relative density of 95%,exhibiting a tensile strength ranging from 120 to 141 MPa and a tensile strain of 1.0%−2.5%.

关 键 词：7075铝合金 金属熔融沉积成型 金属注射成型 显微组织演变 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]